Simple GIS-like app.

Good morning, all.

    I'm want to improve my experience in MVP and Dolphin UI classes, and
as my personal research project I'm going to implement a simple
application, a kind of primitive GIS: it will allow you to visualise and
navigate (scrolling/zoom/search) through a simple vector map.

    Because I kind of new with Dolphin UI, I'll very appreciate your
advices about implementation details, any hints and so on..

    I'm going to use a Canvas, which is slightly bigger than visible
area of display, so I would be able to scroll through it, dinamically
rendering only needed parts of map (from vector form to bitmap form)
with appropriate zoom-factor. Correct?

Thanks in advance,
Vadim.

Vadim Kolontsov wrote:

>     I'm going to use a Canvas, which is slightly bigger than visible
> area of display, so I would be able to scroll through it, dinamically
> rendering only needed parts of map (from vector form to bitmap form)
> with appropriate zoom-factor. Correct?

Roughly, yes.  You don't create a Canvas directly, a View /has/ a Canvas which
you can draw on.  A good place to start is to look at the Bouncing Balls demo
package, and the BouncingBallView in particular.

BTW1, I wouldn't worry about only rendering the needed parts of the display at
first.  Unless you want to use very complicated scenes, or the map is much
bigger than the window, the chances are that the system will be quick enough
without that optimisation.  And much simpler :-)

BTW2, if you decide that you want to add printing to your application, it's
quite easy to adapt your existing code for drawing on a printer canvas.  Except
for one thing -- text.  I won't try to go into details (that I don't properly
understand myself anyway), but don't be surprised that it's not as simple as
you'd expect or hope.  It doesn't mean you are doing anything wrong, or missing
something obvious, it's just the way that Windows printing is :-(

    -- chris